Wireless sensor networks (WSNs) are built from wireless sensor nodes, where each wireless sensor node is connected to one or more sensors for monitoring physical and/or environmental conditions, such as temperature, sound, vibration, pressure, humidity, motion, pollutants, and/or other environmental condition. With the advent of Internet of Things (IoT) and machine-to-machine (M2M) applications, WSNs face challenges with providing network connectivity to sensor nodes, particularly as resource constraints are continually tightened on the sensor nodes. Although existing wireless sensor network communications systems and methods have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects.